I recently did a repair to a 48GX by shoring up the rubber pad which supports the contact strip connecting the keyboard to the PCB. The calc now passes the keyboard test and the self test. However, it now will not beep during testing. The spring is firmly soldered in place, and makes contact with the disc. Any ideas what else it could be? Thanks.

Edited: 5 Mar 2007, 8:41 a.m.

There's improper grounding. Behind the battery holding area (upperhalf of the case) is a piece of metal that has a tab slightly bent away from the rest of the case. This metal tab needs to touch the metal from the lower half. At the moment, you're not getting the proper grounding. Either the lower section of the calculator near the 1, 2, and 3 keys is not properly closed (i.e. the four rivets there have not been reset) or the tab needs to be slightly bent (i.e. it was accidentally flattened out).

Edited: 5 Mar 2007, 9:34 p.m.

Rebent the tab, and that did the trick. Thanks, Han!